Conventionally, when wireline pressure equipment, such as a wireline blow-out preventer (BOP), is installed as part of a drill or production string which extends downwardly from a drilling rig or the like, a standard wireline pressure skid is used to control such equipment. The wireline pressure skid is generally located on the floor of the drilling rig and has a number of valves which control the fluid pressure applied to such equipment. These controls need to be monitored and possibly changed at frequent intervals by an operator located at the skid. No-one else has control over the skid, unless they are adjacent to it.
In addition, existing systems do not allow automatic control of wireline grease injection pressure. This pressure requires adjustment when a wireline is being run into, or out of, a well. Any variations in cable speed or well pressure will result in the wireline grease injection pressure having to be adjusted.